An extensive battery of sensory and cognitive electrophysiological tasks is used to assess sensory, cognitive and performance deficits produced by atropine. The tasks include eyes open and eyes closed EEG, brainstem auditory evoked response, pattern reversal visual evoked response, the auditory rare event monitoring task, auditory continuous performance task and Sternberg auditory memory task (both immediate and delayed). Each of four doses of atropine (0, 2, 4 and 6 mg/70 kg) is investigated on two occasions. Eight subjects have been tested on these procedures. The purpose of the study is to better understand the effects of cholinergic agents on cognition and performance; in particular, where in the information processing sequence atropine exerts its effects. The EEG and evoked response data have been reported in military and scientific journals. Atrophine at doses 4 mg or greater increase EEG slowing and reduces cognitive evoked potentials and performance. The EEG results were published and evoked potential analysis began over the last year.